The upcoming American epic space opera film, "Rogue One: A Star Wars Story," is the next motion picture in the film series "Star Wars" that chronologically come about before "Star Wars: Episode IV.

The Chinese martial artist - Donnie Yen, English actor - Riz Ahmed, and film actor - Wen Jiang, are set to appear in the upcoming American epic space opera film.

The cast and crew of the film are having a hand in the three-day Star Wars Celebration in London this weekend. The behind the scenes footage that features Yen, Ahmed, Jiang and other cast members of the film was released, according to NBC News.

In the footage, Yen, who portrays Chirrut Imwe, was spotted in fight scenes, running through fight choreography with stunt actors, as well as standing in front of the fire. There are also clips that showed Jiang (who plays Baze Malbus) staring at the horizon and Ahmed - who plays a soldier of the Rebel Alliance, Bodhi Rook.

However, the veil of mystery over the upcoming "Star Wars" film was made by the British film director Gareth Edwards, as he took to the stage at the ExCeL London conference center.

Edwards was joined on stage by Felicity Jones (the English actress who portrays Jyn Erso) and supporting stars like the Mexican actor Diego Luna, Ahmed, Yen, Wen, Alan Tudyk and Mads Mikkelsen.

Also on stage were the American actor who plays Saw Gerrera - Forest Whitaker, and the Australian actor Ben Mendelsohn, based on the report of Telegraph.

Lucasfilm president Kathleen Kennedy stated that the film will look and feel unique from all other movies in the franchise. Kennedy also said that when a person will watch the "Rogue One," that person will have an incredibly immersive experience, Star Wars reported.

"Rogue One: A Star Wars Story" will fire up theaters on December 2016.

Watch the behind the scenes here: